The invention concerns an improved window, the casement of which is mounted on pivots in its associated frame.
Double glazing and well as triple glazing windows have been developed lately in which the window panes are treated to prevent strong heat radiation from penetrating the glazing. Instead, part of the heat radiation is reflected back into the atmosphere. In this manner it has become possible to prevent powerful sunlight from heating the premises in a building excessively during the summer, with resulting economy of for instance the energy required to operate an air conditioning system. In many cases it has also become possible to do without Venetian blinds.
However, as summer progresses into autumn and winter, the conditions are the opposite ones. During this period it is desirable to prevent thermal energy in the heated premises from radiating through the windows and into the atmosphere.
From the Swedish Patent Specification No. 505 297 is known a device by means of which a casement may be pivoted from a closed position with respect to a frame, over half a turn into a reversed, closed position, and to lock the casement in said closed position. Following its release, the casement may be pivoted from the closed position, either further in the same direction or backwards in the opposite direction. In this manner the device offers the user a choice of which side of the window he wishes should be directed outwards and which to be turned inwards during a certain period.
In order to lock the casement in the closed position thereof the frame is fitted with a locking mechanism comprising a rotatable member and a catch, the latter being movable into and out of a casement securing position adjacent a stationary guide bushing mounted on the window frame. To this end, the frame must be formed with a transverse groove which is open towards the atmosphere and which runs into a longitudinally extending groove designed to guide the guide bushing, to ensure that the latter travels towards the locking mechanism upon closing of the casement and outwards, into the open air upon pivotal movement outwards of the casement.
The object of the subject invention is to simplify the construction defined above. This object is achieved by the provision of a rotatable lever mounted in the casement or the frame and by means of which guide bushings may be extended or retracted simultaneously in pairs out of respectively into said grooves. This arrangement obviates the need for a separate catch, and the longitudinal grooves no longer need terminate in a transverse groove. Yet, the same possibilities as before are available, in that when the casement has been pivoted over half a turn in the reverse direction and closed and locked in said reversed position by retraction of one of the pairs of guide bushings, the casement may be pivoted in the reverse direction, or its pivotal movement in the same direction as originally may be continued by retraction of the opposite pair of bushings.